Kerite.



UNTTED STATES PATENT OFFICE.

IVILLIAM R. BRIXEY, OF SEYMOUR, CONNECTICUT.

KERITE.

SPECIFICATION forming part of Letters Patent N0. 714,859, dated December 2, 1 2- Application filed April 18, 1902. Serial No. 03,583

To all whom it ntay concern:

Be it known that LIVILLIAM R. BRIXEY, of Seymour, in the county of New Haven and State of Connecticut, have invented an Improvement in Kerite; and I hereby declare that the following is a full, clear, concise, and exact description of my invention and of the best mode known to me of putting the same into practice.

Kerite was originally invented and applied to practical employment for electrical uses by the late Austin G. Day. by him it was composed of her combined with the compound which he termed crude kerite, the india-rubber in this combination furnishing the insulating property and the crude kerite imparting the necessary permanency and the capacity to resist deteriorating influences. This crude kerite compound was also originally invented by him, and different modifications of it were made the subjects of many Letters Patent of the United States which were granted to him. In his best practice with it the compound always consisted, essentially, of a miX-- ture of cotton-seed oil, linseed-oil, coal-tar, bitumen, asphalt, and sulfur, the latter being employed partly in its ordinary form and partly in the form of sulfid of antimony, and the combined ingredients being subjected to high temperatures for the required heating periods to first thoroughly incorporate them into 'a homogeneous vulcanize the mass. this compound was mechanically united with the india-rubber by grinding in rolls substantially in the manner in which such rolls are employed by manufacturers of various kinds of india-rubber goods-that is, the

crude kerite was ground first, then the rubher with litharge and someother substances, and finally the two materials were ground together and vulcanized. Isucceeded to Days business and to the ownership of his kerite patents, and by long-continued manufacture of his kerite products and close study of the nature of the elements which enter into them Ihave discovered a method of makinga crude kerite which is far superior to the Day crude compound, and by combining this with india-rubber I am enabled to produce a finished kerite which not only greatly As manufactured I natural india-rubbody and afterward to WVhen thus prepared;

(N0 specimens.)

surpasses that of Day in its capacity of electrical resistance, but also can be manufactured at very much less cost. My process of making this improved crudekerite compound forms the subject of other Letters Patent of even date herewith and is fully described therein, and the nature of my improvement herein set forth consists in producing a finished kerite by combining theindia-rubber with this special crude compound which I have invented, and thereby imparting to the completed product the greatly-increased electrical resistance which has been referred to, while at the same time largely diminishing the cost of its manufacture.

In order that my invention may be put to practical use by others, I will first here recite the method of making myimproved crude compound as the same is set forth in my other Letters Patent above mentioned.

For an ordinary working batch of the crude keritesay about one hundred and eighty pounds in allI generally first take twentyfive pounds of coal-tar and fifteen pounds of asphalt, put them together in a kettle or other suitable boiler or vessel,'and heat them up to 350 Fahrenheit for one and one-half hours. I next add seventy pounds of linseed-oil to the mixture and again heat the whole to 350 for seven hours. At this stage of the working the three ingredients are well prepared to be united into a homogeneous mass, and I then let the mixture stand over night to allow this union to take place. In the morning they will be found to be thoroughly combined, and I then once more heat the mass up to 240,and as soon as it reaches this temperature I add to it ten pounds of sulfur, the latter being in its ordinary form and not in the form of a sulfid, and continue the heat at an increased temperaturesay about 320for about half an hour. At the end of this time I add four pounds more sulfur and run the heat up until the temperature reaches 300' or thereabout, and then put in about fifty-six pounds of talc and keep the heat up at about the same temperature until vulcanization of the entire mass takes place, which will usually be in about one-half to three-quarters of an hour after the tale is added. The batch is now finished and the crude kerite when cooled is ready to be mixed with the natural india-rubber. The addition of the tale to the other ingredients is not absolutely necessary to the making of a good crude compound, but its use will be found to give such an increased adhesiveness to the material and to render the latter so much better adapted to combine with the india-rubber to produce the finished kerite that I strongly recommend its employment in all cases.

The foregoing extract from my other Letters Patent fully describes my new crude kerite compound, and when it has been thus prepared I proceed to incorporate it with the natural india-rubber by grinding the two together in the rolls, employing such suitable proportions of the crude kerite and the rubber as may be best adapted to the purposes for which the finished product is to be used. For example, if the kerite is intended for the insulation of aerial wires or cables I use about one-fifth part of natural rubber to four-fifths of the crude compound. If the insulation is designed for underground conductors, about two-fifths parts of rubber to three-fifths of the compound should be employed, and if it is to be used for submarine cables then about three-fifths of rubber to about two-fifths ofthe crude kerite will be a suitable proportion. In the practical operation of combining the crude compound with the natural rubber in either of these mixtures I first grind all of the crude kerite which enters into the mixture till it comes to a warm homogeneous mass. Next I put into the rolls all the rubber, together with about ten pounds of litharge and about ten pounds of oxid of zinc, the litharge being used in the ordinary way to aid the subsequent vulcanization of the mass, and the oxid of zinc being also employed, as is customary, to render the finished product more solid and to prevent its oxidation. I also generally add to the rubber about six pounds of chicle or prefer ably the same quantity of what is called Oolumbian gum, which is a substitute for chicle and costs only about half as much and answers a better purpose, the effect being that the adhesive nature of these substances, whichever one be employed, causes the rub ber and the other ingredients to combine very thoroughly. The rubber and these added materials are then ground together till they are well mixed, and as soon as this is effected the already-ground crude compound is put with the ground-rubber mixture and the combined mass is further ground until all the ingredients of it are thoroughly united together. The product is now ready for vulcanization, and to eifect this I add to it a small quantity of sulfur-say about five pounds to each working batch of about seventy-five pounds of the combined materials; but before the vulcanization is performed and while the mixture is still plastic I proceed to spread it upon the wires which are to be used for the electrical conductors in the usual covering-machines. When the wires are fully covered, I vulcanize the kerite coating in the ordinary way, employing for the purpose a heat of about 260 to 280 Fahrenheit. This final vulcanization of the coating completes the work and converts the combination of the crude compound with the natural india-rubher into the finished kerite. An analogous operation is to be followed in all cases in which the finished kerite is to be employed for any of the other uses to which it may be adapted. No particular proportions of the crude compound and of the natural rubber need be specified for any of these other uses, as the proportions may be greatly varied and in each instance will depend upon the special purpose for which the product is designed; but the insulation of electrical wires and cables is the chief object to which the kerite has hitherto been applied, and for that reason this specification has been mainly limited to that matter.

It will be found that my improved finished kerite made with my special crude compound, as here described, will by actual test develop an electrical resistance at least twice as great as that of the Day product, while the omission of the cottonseed oil from the crude compound will by largely reducing the expense of manufacturing that compound, as set forth in my above-mentioned other Letters Patent, enable me to combine the natural rubber with a crude kerite costing fully forty per cent. less than it could be produced by Day. At the same time all the valuable qualities of the Day compound remain unimpaired in my kerite. It withstands the effects of climate and of sunlight and of all the decomposing agencies of earth and sea. It is impervious to the action of ozone, and its high insulating capacity endures under all circumstances, unaffected by rain or moisture, while the rubber which imparts this capacity to it is enabled to easily resist acids, alkalies, and all the hitherto known rubber solvents.

Having thus declared my invention, what I claim, and desire to secure by Letters Patent,

The specific process herein set forth of making an improved kerite by combining the above mentioned special crude compound made with natural india-rubber and vulcanizing the mixture, substantially as described.

WVILLIAM R. BRIXEY.

Witnesses:

J. E. PALMER, GEO. F. PORTER. 

